No fruit juice and good natural food with no additives for three weeks and parents will see a big change in their children, Julienne Law of Kerikeri says.

Mrs Law is a key member of a national Brain Food for Better Learning group and would love to see Far North schools attach "additive free" to their "smoke free" status.

Mrs Law has more than 30 years experience as a primary school teacher in New Zealand and overseas.

She has been working with doctors, health professionals and teachers on combating poor concentration due to poor eating habits.

"Poverty is in focus nationally and tests show there is a link between low income and under-achievement in New Zealand.

"But it is not just children from low income families who don't eat a good breakfast before coming to school. I am convinced that the wrong diet is often the root of behavioural issues.

"Some schools are already well down the track but I would love our schools to conduct a three week, additive free trial - perhaps starting with one year group or one class, with kids involved in setting up the trial."

She believes that keeping artificial chemicals out of diets and drinking water can change behaviour problems and promote calm and happy families.

"If families make the effort to keep their families additive free they can avoid abuse scenarios."

"Eating for success" trials in South Australian schools produced positive results, expanding from family participation to whole classes and entire schools, Mrs Law says.

"Children found schoolwork easier but the biggest improvement was with sleep," she says.

As an example, she relates her own experience with a child in Saudi Arabia.

"An 8-year-old early emergent reader with severe behaviour problems was transferred from the British year 1 class to my kindergarten class of 5-year-olds in the American school. By the end of that school year, he was reading at his chronological age of nearly 9.

"When additives and fruit juice were excluded from his diet his mood, health, learning and behaviour all improved so much that he was no longer excluded from the classroom and made many friends."

In New Zealand, additives banned many years ago in Scandinavian countries are still being used in foodstuffs attractive to children, she says.

"Finland and Scandinavian countries have high levels of literacy. I believe it is because many additives have been banned or never introduced into the food chain of Scandinavian countries. Visit schools in Rarotonga with enormous class sizes and see not one child annoying the group. Cook Islands children do not have the money for junk food and eat from family gardens."

Present better choices for the family - no additives, colours, preservatives in the diet, no fruit juice - and no perfumes, cleaning agents, soaps, air fresheners.

"Teachers of many years experience have noticed a marked deterioration of health, behaviour and learning of pupils. Children are coming to school without breakfast and unable to sustain learning throughout the school day. These children don't want to be ill, unhappy or not to learn," Mrs Law says.